Dion and the Belmonts were an American doo-wop group, formed in the late 1950s in the Bronx, New York. Comprised of lead singer Dion DiMucci, Carlo Mastrangelo, Fred Milano, and Angelo D'Aleo, the quartet is known for their harmonious vocal style and rock and roll beats. Their notable hits include "A Teenager in Love" and "Where or When", which have significantly contributed to the development of the doo-wop genre. Dion DiMucci's distinctive, smooth lead vocals set the group apart in the music scene of their time.